A multi-site EDRN collaborative project, approved by the EDRN Executive Committee, is focused on the validation of protein biomarkers for the early detection of Ovarian Cancer. Approximately 150 such biomarkers have been contributed by six EDRN sites (Biomarker Development Laboratories and Clinical Validation Centers), which were discovered during previous EDRN funding cycles. The biomarkers have been subjected to initial prioritization using bioinformatics-based approaches as well as the empirical method of Accurate Inclusion Mass Screening (AIMS), developed by Dr. Steve Carr at MITs Broad Institute and member of the Harvard OC BDL. Two EDRN Biomarker Reference Laboratories, including Pacific Northwest National Laboratory (PNNL) will participate in the project to develop highly specific assays for the quantitative verification of the 50 top-ranking biomarkers in plasma of 40 OC cases and 40 benign pelvic-mass controls. Due to the lack of high-affinity antibodies for 25 of the high-priority candidate biomarkers, PNNL will develop antibody-free mass spectrometry assays using Selective Reaction Monitoring (SRM).